What happened
On 22 October 2011, a Britten-Norman BN.2A Mk.III-2 Trislander was preparing for a scenic charter flight departing from Pauanui Beach aerodrome. The aircraft, operated by Great Barrier Airlines Limited, was carrying 13 people, including the pilot, one company employee, and 11 passengers.
During the takeoff roll, the pilot applied full power; however, the aircraft failed to lift off the ground. In response, the pilot aborted the takeoff and applied maximum braking. Despite these efforts, the aircraft could not be stopped before reaching the end of the runway. The plane breached a low wooden rail at the runway's edge and came to a halt with its nose wheel embedded in a garden, approximately 3 metres from a public footpath. There were no injuries reported, and the aircraft sustained only minor damage.
The investigation
The investigation focused on why the aircraft failed to achieve flight and why the aborted takeoff resulted in a runway excursion. Investigators examined the aircraft's loading, the pilot's performance, and the runway conditions. The inquiry also looked into the regulatory oversight of the operator and the infrastructure of the aerodrome itself.
Findings
The investigation established that the primary cause for the failure to become airborne was that the aircraft's center of gravity was significantly outside of permissible limits. This imbalance prevented the aircraft from achieving the necessary aerodynamic performance for takeoff.
Several contributing factors were identified regarding the overrun. The aircraft's weight exceeded the safe margin for the available runway length, making it difficult to stop once the takeoff was rejected. Additionally, the pilot's specific takeoff technique and potential increased rolling resistance from the heavy aircraft's wheels on the runway surface contributed to the excursion.
Safety action
Several systemic safety issues were identified during the inquiry:
- The operational management and pilot training standards at Great Barrier Airlines were found to be below the necessary requirements.
- The Civil Aviation Authority of New Zealand had previously noted concerns regarding the airline's operations, but prior interventions had not effectively resolved these issues.
- The Thames-Coromandel District Council had not assessed how a subsurface runway irrigation system might affect the maximum equivalent single wheel load (ESWL) for the Pauanui Beach runway.
As a result of these findings, recommendations have been issued to the Director of Civil Aviation and the Chief Executive of the local council to address these operational and infrastructural safety gaps.